1. Field of the Invention
The present invention relates to a waterproof connector housing and a method of manufacturing the same, and also to a mold used in manufacturing the same.
2. Related Art
FIG. 4A is a sectional view of a connector housing a of the prior art. In FIG. 4A, reference numeral a1 indicates a connector housing main body, and a hood portion a3, required for engaging a mating housing (not shown), expands from the connector housing main body via stair portions a2. Inside the hood portion a3, an elastic seal ring a4 is provided for maintaining water-tightness between the hood portion a3 and the mating housing.
FIG. 4A is a sectional view of a connector housing a of the prior art. In FIG. 4A, reference numeral a1 indicates a connector housing main body, and a hood portion a3, required for engaging a mating housing (not shown), expands from the connector housing main body via stair portions a2. Inside the hood portion a3, an elastic seal ring a4 is provided for maintaining water-tightness between the hood portion a3 and the mating housing. This elastic seal ring a4 is provided with slip-off preventing pieces a5 which engage with slip-off preventing holes a6 so as to prevent the elastic seal ring a4 from slipping off at the time of insertion or pulling-out of the mating housing. A terminal receiving chamber a7 for receiving terminals is provided inside the housing main body a1, and terminal stopping pieces 8 for stopping terminals are provided inside the terminal receiving chamber a7. A terminal receiving chamber a7 for receiving terminals is provided inside the housing main body a1, and terminal stopping pieces 8 for stopping terminals are provided inside the terminal receiving chamber a7.
The above waterproof connector housing a is manufactured as follows. As shown in FIG. 4B, an intermediate product integrally consisting of the housing main body a1 and the hood portion a3 molded by injection molding is set beforehand in a cavity formed by an upper mold b1 and a lower mold b2. An elastic material or its raw material (hereinafter referred to as "elastic raw material") is introduced into elastic seal ring cavity portions b4 from elastic material introducing portions b3 provided on the lower mold b2 through the slip-off prevention piece holes a6 of the hood portion a3. After that, the elastic seal ring a4 is formed by curing and/or reaction, and the mold is then opened to take out the obtained waterproof connector.
This waterproof connector is less likely to lose the elastic seal ring, and exhibits an excellent water proofing ability. However, there is a problem that less freedom is allowed in design when providing a locking mechanism for locking a mating connector to the hood portion or forming irregularities for preventing wrong connections. If the engaging area between the slip-off prevention pieces a5 and the prevention piece holes a6 is increased to improve reliability in preventing slip-off of the elastic seal ring, the hood portion of the corresponding portion has to be thickened accordingly, resulting in increases in size and weight of the hood portion. This is very disadvantageous in such a field as car manufacturing in which many wires need to be arranged in a small space.
Another disadvantageous point of the conventional waterproof connector in car manufacturing is that since a runner inside the mold has to detour around the hood portion a3 in FIG. 4B, which is the thickest part in the connector housing, so as to be connected to the two elastic material introducing portions b4, the path for the elastic raw material becomes long, and it is troublesome and time-consuming to take out the material cured and reacted inside the runner. In such case, the raw material is often wasted. If the two elastic material introducing portions b4 are merged into one, a short shot is caused, reducing yield as well as reliability in waterproofing.
The above disadvantages in manufacturing cannot be avoided even if a housing c shown in FIG. 4C is employed. In this housing c, a hood portion c3 is formed as an expansion from a housing main body c1 via stair portions c2. The housing c is the same as the housing a in that an elastic seal ring c4 is provided inside the hood portion c3, but slip-off prevention pieces c5 of the elastic seal ring c4 are engaged with slip-off prevention piece holes c6 formed at the stair portions c2.
When molding the elastic seal ring c4 in such case, the runner of the mold detours around the housing main body, which is thinner than the hood portion. Thus, the disadvantages in manufacturing can be eliminated to some extent. However, the stair portions c2 still need to be larger than the slip-off prevention piece holes c6. Because of this, it is difficult to shorten the outer diameter of the hood portion c3, and there is a limit to the design of the hood portion c3. Furthermore, various irregularities often need to be formed on the side surfaces of the housing main body. In such case, it is difficult to secure the elastic material introducing portions, and there is a limit to the design of the housing main body.